I have a love hate relationship with sippy cups. On one hand I love them because they keep toddlers from spilling, staining and making big messes. And I am certain that on many occasions they have kept me from getting into a car accident as my toddlers have hurled their cups onto the floor board and I didn't have to worry about spills. But unfortunately, sippy cups are the petri dish for many harmful bacteria that can cause illness.

If you think that washing a sippy cup with soap and hot water before filling it with fresh milk or juice protects your child, think again. Within minutes, dangerous bacteria can multiply inside that plastic cup, exposing them to a variety of illnesses - some that could have serious long-term health implications.

Each year, more than 800,000 food-related illnesses directly affect children. The Food and Drug Administration reports that in some cases, these children will suffer long-term health problems, including kidney failure. Children, the elderly and people with compromised immune systems are at highest risk for death from food-borne illnesses.

A recent study by Cornell University indicates that many non-insulated sippy cups on the market today don't inhibit the growth of illness-causing bacteria. In fact bacteria can double in as little as 10 minutes. They placed cold milk in a variety of sippy cups, added 250 bacteria per teaspoon of milk, and allowed the cups to sit at room temperature for 16 hours. At the end of the test, bacteria had multiplied in the range of 50,000 to 250,000 per teaspoon in nearly every cup. Normally we would not let a cup sit at room temperature for more than an hour, but those cups designed to be spill-free can pose a huge problem because the ooey-gooey gunk that can get stuck inside the small valves, or straws are a breeding ground for bacteria and mold, plus they thrive in sugary environments. Use sippy cups without the valves or take them apart washing and sanitizing them thoroughly after each use.

Now for you adults who use sippy cups - I mean water bottles. The same sanitation rules hold true for cleaning and sanitizing your water bottle. First, don't store your water bottle with the lid on. New nasty life-forms can easily grow in this dark and moist environment that can really make you sick. Secondly, sanitize your water bottle or sippy cup. You can do this by putting it in the dish washer, but that doesn't necessarily kill the bacteria hidden the cap. Here are some other solutions:

Bleach Method: Dilute 1 teaspoon of bleach and 1 teaspoon of baking soda in a 4 liters of water. Fill your water bottle with the solution and let it sit overnight. Squeeze some of the solution out so that it gets into the cap area. Rinse the bottle in the morning and let it air dry, inverted on the dish rack. Store it in a dry place with the lid off.

Freezer Method: Wash your bottle in warm soapy water. Rinse it well and then stick it in the freezer until you're ready to use it again. Most bacteria and mold don't survive in freezing temperatures.

White Vinegar Method: Use the same procedure as bleach, only fill 1/5 to 1/4 of your bottle with white vinegar and the remainder with water.

Dr. SeAnne Safaii, Ph.D., RD, LD, is an assistant professor at the University of Idaho.